/* ====================================================================
 * Copyright (c) 2014 - 2017 The GmSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the GmSSL Project.
 *    (http://gmssl.org/)"
 *
 * 4. The name "GmSSL Project" must not be used to endorse or promote
 *    products derived from this software without prior written
 *    permission. For written permission, please contact
 *    guanzhi1980@gmail.com.
 *
 * 5. Products derived from this software may not be called "GmSSL"
 *    nor may "GmSSL" appear in their names without prior written
 *    permission of the GmSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the GmSSL Project
 *    (http://gmssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE GmSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE GmSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 */

#include "modes_lcl.h"
#include "rotate.h"
#include "sms4.h"
#include "sms4_lcl.h"

#define L32(x) \
    ((x) ^ ROL32((x), 2) ^ ROL32((x), 10) ^ ROL32((x), 18) ^ ROL32((x), 24))

#define ROUND_SBOX(x0, x1, x2, x3, x4, i) \
    x4 = x1 ^ x2 ^ x3 ^ *(rk + i);        \
    x4 = S32(x4);                         \
    x4 = x0 ^ L32(x4)

#define ROUND_TBOX(x0, x1, x2, x3, x4, i) \
    x4 = x1 ^ x2 ^ x3 ^ *(rk + i);        \
    t0 = ROL32(SMS4_T[(uint8_t)x4], 8);   \
    x4 >>= 8;                             \
    x0 ^= t0;                             \
    t0 = ROL32(SMS4_T[(uint8_t)x4], 16);  \
    x4 >>= 8;                             \
    x0 ^= t0;                             \
    t0 = ROL32(SMS4_T[(uint8_t)x4], 24);  \
    x4 >>= 8;                             \
    x0 ^= t0;                             \
    t1 = SMS4_T[x4];                      \
    x4 = x0 ^ t1

#define ROUND_DBOX(x0, x1, x2, x3, x4, i) \
    x4 = x1 ^ x2 ^ x3 ^ *(rk + i);        \
    x4 = x0 ^ SMS4_D[(uint16_t)(x4 >> 16)] ^ ROL32(SMS4_D[(uint16_t)x4], 16)

#define ROUND ROUND_TBOX

void sms4_encrypt(const unsigned char in[16], unsigned char out[16],
                  const sms4_key_t* key)
{
    const uint32_t* rk = key->rk;
    uint32_t        x0, x1, x2, x3, x4;
    uint32_t        t0, t1;

    x0 = GETU32(in);
    x1 = GETU32(in + 4);
    x2 = GETU32(in + 8);
    x3 = GETU32(in + 12);
    ROUNDS(x0, x1, x2, x3, x4);
    PUTU32(out, x0);
    PUTU32(out + 4, x4);
    PUTU32(out + 8, x3);
    PUTU32(out + 12, x2);
}

/* caller make sure counter not overflow */
void sms4_ctr32_encrypt_blocks(const unsigned char* in, unsigned char* out,
                               size_t blocks, const sms4_key_t* key,
                               const unsigned char iv[16])
{
    const uint32_t* rk = key->rk;
    unsigned int    c0 = GETU32(iv);
    unsigned int    c1 = GETU32(iv + 4);
    unsigned int    c2 = GETU32(iv + 8);
    unsigned int    c3 = GETU32(iv + 12);
    uint32_t        x0, x1, x2, x3, x4;
    uint32_t        t0, t1;

    while (blocks--) {
        x0 = c0;
        x1 = c1;
        x2 = c2;
        x3 = c3;
        ROUNDS(x0, x1, x2, x3, x4);
        PUTU32(out, GETU32(in) ^ x0);
        PUTU32(out + 4, GETU32(in + 4) ^ x4);
        PUTU32(out + 8, GETU32(in + 8) ^ x3);
        PUTU32(out + 12, GETU32(in + 12) ^ x2);
        in += 16;
        out += 16;
        c3++;
    }
}
